A study on development of the thermal storage type plate heat exchanger including PCM layer

Thermal storage type plate heat exchanger (TSPHEs) was newly developed in the process of research a heat pump using industrial waste heat as a heat source for evaporation. A conventional plate heat exchanger is a structure in which two media perform heat transfers through a separation plate. However, TSPHEs have a structure in the basic structure of conventional plate heat exchanger adding the PCM layer filled to phase change material. Therefore, the TSPHEs performed heat exchange between three heat media (hot water-cold water-PCM). The thermal energy supplied through the hot water is mainly transferred to the cold water and some of it is transferred to the phase change material filled in the PCM layer. When if the hot water is shut down and the heat source can’t be supplied, the heat stored in the PCM layer is transferred to the cold water through the hot water, the medium of transmission. In the article, using the ε-NTU method, a thermal equilibrium equation is established between the three heats media used in the TSPHEs. Based on the established theoretical formula, the relationship between total overall heat transfer coefficient and ε, S (temperature differential), and C_r (heat capacity ratio) was obtained. In addition, the validity of the theoretical analysis was demonstrated through the experimental method and compared with the correlation of the existing overall heat transfer coefficient. The results of this article will be utilized as basic data for the design of the TSPHEs, and will be used to predict the amount of heat exchange and thermal storage capacity of the TSPHEs.